X-ray diffraction device



July 14, 1953 l s. 1'. GRoss 2,645,720

' XLRAYYDIFFRACTION DEVICE Filed nec. 1s, 195o ATTO 'I -I The X-ray sourcef-or the '.inventionis an Iarticiallyradioactive isotope.

Patented July 14, 1953 l UNITED A-sfrA'r1=:.s inxiENTN OFFICE N. 1 f I- 2,645,720 Y .I p

` X-:RArpiFFRACTioN DEV-Ice (Siegfried T; Gross, Easton, Pa., assigner to General Aniline &j.Film Corporation, New York,

N.`Y., a corporation of Delaware Application December 13, 1950sr'ia1uaz0040 The present invention relates X-ray diffraction device. The industrial .and research uses of X-ray diffraction methods are Wellvknwn; such methods can be readily used, for exampla'inidentifying andquantitatively analyzing for crystalline ma terials, for the measurement of particle sizes in the colloidal and sub-colloidal range, rfor lthe orientation of crystals (i. e., inthe manufacture of quartz plates for velectronic oscillators), to measure `orientation in bers, in the study of detergent and soap solutions, surface films, Vand toA obtain information regarding the detailed struc-*I sults obtained, evenduring a short period of time.

1t is an object of the present invention to provide an improved X-ray diffraction device.

to anA improved .I Z'Claims. (01.250-53) 1 It is a `further object ofthe present invention to `provide an improved X-ray diffraction' device not requiring the use of an X-ray tube.

These and other objects -are attained by the present invention which isidirectedto a device comprising a cameraorlthelike, a radioactive isotope X-ray source and preferably means-for focusing the X-rays.

For example, radioactive ',-iron 55 is unstable in devicerof the present i such a manner that it captures one of-its K elec- I trons Y changing to manganese. orbit is immediately lled by an outer electron, and thus the atom emits the characteristic K X-ray spectrum for manganese. About a millicurie of iron 55 yields sufficient intensities suitable for making diffraction patterns. Y Ina similar manner, radioactive YZinc vWhich yields the a X-ray spectrum for copper may be used as Well as antimony and others. Depending upon the purity-of the material, more or less lead shielding single slit Vand be brought much closer to the 'I'he vacated K 1 I 2 Y Y source than is possible with previous conventional equipment.` The half life ofV iron 55gis -aboutfive years, and thus Within any short space of time very consistent results .are obtainable'.

The source can be encased in a suitable shield#V I ed-container equipped with means to support the diffractionequipment, and equipped with safety doors lto make the equipment completely safe. With iron"55 the shielding of metal can be quite thin since the radiation obtained is quite long in Wavelength, approximately 2 A. U. (2)(10-8 Preferred embodiments ofl the invention Iare lshrotvn in the drawings, wherein:

` Figure 1 isa diagrammatic view of a 'camera according' to the present invention, V'Figure 2 isa diagrammatic vieW of an alternative device particularly adaptable for` detectingV strain in boilers, andv Figure 3 is an alternative device to the one illustrated in Figure 1. Y

In Figure l1V there is disclosed the preferred embodiment of the invention which is a `camera having` a suitable housing I0 wherein there is suspended a metalplate II, the surface I2 of which has a radioactive materialplated on. -Ad`V jacent to `th'e` surface of Vthe plate is a focusing `Soller"'slit I3 which is made. up of a number of l `Only a `fevv shims `are indicatedf Whereas inthedevice itself a considerably larger Sample holding thin shims.

number "of shi'ms are used. means I4 is arranged in front of the `slit and contain-s lasample such as a screen coated with a powdered sample of the material being tested. 'lhe body of the camera is divided into two principal areas i8 and i9. 'In each area Ythere is an outer` Wall 20 and an innerWall 2l forming a` lm holder. `Openings 22 and 23 are adapted to allow lm tovbe placed inthese ilmholders surrounding areas i8 and I9. A beam stop 25 surrounds an aperture 26 separating areas I8 and I9 causingafocus of the X-rlays. A second samplevholding means 21 Vis located at the opposite end .of area I9 from aperture 26 and is adapted to contain :a sample Whose back reiiectlon isrto be measured. It will be understood that the sample holding means I 44 and 21 will be used alternatively, depending upon Whether a transmissionV or back reflection of the sample is I desired. For transmission the solid lines show 'hoW the focus occurs, and for back reflection the dash lines indicate the behavior of diilracted radiation.

With reference to. Figure 42, there isillustrated diagrammatically a camera which is particular-` ly adaptable for detecting flaws in boilers or tank Walls, having a suitable housing 30 wherein there is suspended a metal plate 3|, the surface 32 of which has a radioactive material plated on. Adjacent to the surface of the plate is a focusing Soller slit 33 which is made up of a number of thin shims. Attached to housing 30 are a plurality oftlegsll 34 adapted to loe-held against' vmade out of any oi a number of materials The shims of the Soller slit may be isotope.

including mica.

It will be understood that preferred forms .ofc the invention are illustrated and that variations and modications may be made within the Vscope of the claims.

the surfacewhosediffraction is to be measured,

.such as a boiler wall. The legs 34 support nlm holding means which may comprise merely as pack of` X-ray lm clamped to thaleg., Itwill.

, be seen that the Soller slits in this ca'seare` ar= ranged in the opposite manner. fromthoseein j Figure 1, since this deviceisi intended.,foriback;

reflection measurements.

AI'fclaimnl Y ,L g .11... A .'diiracl2-lion.; devicee.comp1ising a housing, a plate within said housing-coated with a radioactive isotope as the source ofV characteristic radiation,a S.0ller slit adjacent to said plate, means for holding'asample at the opposite end of said slit' from; said plate;a-photographic nlm holding With reference to Figure 3, there is.illustrated., l

an alternative camera device comprising a housing 3l', a fine straight wire 38 coated withradi'ce active-isotope, and a slit39 adapted to coincide Witligtl'ieV elongation-oftheawire. In front of. the A slit is a` samples-holder. 4B adapted to contain, al sample',J as forinstances apowder distributed on'. a thin screen. Beyond the sample holder isafilm; holdinggmeansr l.V lwhich may; be .flat-for semicircular.

vIt, will be understood that inplaceof the ,lrn Y inr-these-cameras a; Geiger counter may be used. Eorexample, in the device'` of Figure'l .a Geiger counter; can be movedaround the circular con-Y iining.y areas I8 and I9. Wherethe intensityV of the radiation is suflicient a iluorescent screen,

and photocelkmay be usedfin place of the film.

Other modicationsonthe.device Will occurzto .those-skilled, inthe, art.. For example, a device may beV made somewhat similarto .that shovvnin. Figure 3. whereina. radioactive isotope coated on. astrai'ght wiremaybe used with focusing meansy to direct the rays to a sample, butthelm maybe; arranged. around the .-focusing. means so ,as to measure `back reflections rather. .than transmitted asin Figure, 3. Theradioactive isotopey is preferably plated onthesame kind of metal lfrom. which the isotope Was derived, yandit may be der-,- sired y,tdhavethecameraparts exposed to .the .rays of; the same` material.

y, Radiation from .radioactive isotope means. as. illustrated 'has a great. advantage. over thatob- Vtained .with Yconventional, equipment in..that it. is

a mixture of.'l four monochromatic-wavelengths.. with .perhaps 95% of,A the, energy in 'one.of..the.

wavelengths. A

The. casingofthe diiraction...device may be. built ofjany suitable material, such as' steel.` Howeverysteel should' not be usedwherecopper radiation" is present. The entire devicelmaybe.

shielded with lead, and the amount of thisshield.`

ine; may' be determined'. by the impurity of the means-'arranged asia semi-circle about said samplefh'olding means at the opposite side from said plate, an. aperture insaid lm holding means directly opposite,y said sample holding means, and

-aisecond sample holding means and a second film holding means adapted .to surround the area be.- tween'said apertureaand said1secondasample holding means.

2:-A lll-diffractiondevice.comprisingl a housing, a

piatezfwithin.saidnousingcoated with a radio,-

ac-tiver--isotopeaoiiron 55, asthesource of charac- 'teristic.radiatiomA a ,Sollen slit adjacent to said Y Y' plate-means for holdingVV a sample at the opposite'lend'zof saidslit vfromsaid plate, a photographic;

fumi-holding,h means 'arranged as. a-.semi-cirole aboutlsai-dsample 'holding-,means at theV opposite side 'fromsaidz plate, an aperture in said i'llm. A holding meansgdirectly oppositesaid sample holding; means. and .ai second sample holding means` and a second nlm holding means adapted to sur-- round. the fareaf between. saidaperture and. said second. sample :holding-means. v

` ofrnEn REFERENCES Focusing: X-Ray Monochromators, by'Y C. lS.

Szrrith: Review of:v Scientific Instruments, June Rays:andflGamma-RaysY byJ. W. Du Mond,A Re:- view1.-of-;-'Scientiiic Instruments, September 1947,v 

